1. Field of the Invention
The present invention generally relates to a telephone device, and in particular to a technique of data communication between telephone devices.
2. Description of the Related Art
There has been disclosed a multi-function telephone device allowing a desired phone number to be called up to a display screen even in conversation with the other party in Japanese Patent Application Unexamined Publication No. 59-228454. In phone conversation, it is of frequent occurrence that one party asks the other about the phone number of a third party. In such a case, it is very convenient to call up a desired phone number from a phone directory memory while maintaining the telephone line.
On the other hand, a telephone device allowing a phone number to be input by the user even in conversation with the other party has been disclosed in Japanese Utility-model Application Unexamined Publication No. 5-91057. This telephone device further allows a calling operation using a phone number registered in a phone directory memory. Therefore, after registering the phone number of a third party heard from the other party, the user can easily make a call at the phone number of the third party by calling up it from the phone directory memory.
In the case of the above-described conventional telephones, however, the user is likely to input erroneous phone numbers in the phone directory memory, resulting in frequently dialing a wrong number.